Viscoelastic surfactant cleaning fracturing fluid gel breaker and field construction method

Abstract

The invention relates to fracturing fluid used by a fracturing production increase measure of an oil-gas field and a construction method, in particular to a viscoelastic surfactant cleaning fracturing fluid gel breaker and a field construction method. The viscoelastic surfactant cleaning fracturing fluid gel breaker is characterized by being formed by compounding saturated hydrocarbon, saturated fatty acid and petroleum ether, wherein the compound ratio of the saturated hydrocarbon to the saturated fatty acid to the petroleum ether is 1-2:1:3; the saturated hydrocarbon is one of various C6 toC20 n-alkanes, the chemical formula of the saturated hydrocarbon is CnH2n+2 and n is a natural number in the range of 6 to 20; and the saturated fatty acid is one of C10 to C20 straight-chain saturated fatty acids, the chemical formula of the saturated fatty acid is CnH2nO2 and n is a natural number in the range of 10 to 20. The gel breaker has the characteristics that the using amount is small, gel is broken rapidly and completely, gel breaking time can be easily controlled at site and the like.

Description

technical field [0001] The invention relates to a fracturing fluid used in oil and gas field fracturing stimulation measures and a construction method, in particular to a viscoelastic surfactant cleaning fracturing fluid gel breaker and an on-site construction method. Background technique [0002] The currently widely used water-based guar gum fracturing fluid does not break the gel completely, resulting in difficulty in flowback and damage to the fracture conductivity by the residue after the gel breaks. Although the viscoelastic surfactant fracturing fluid does not contain solid residues and has little damage to fractures, it is difficult to break the gel for ultra-low permeability and low-yield oil layers or natural gas and coalbed methane reservoirs, and the effect of flowback and sand discharge is poor; therefore, When using viscoelastic surfactant fracturing fluids for low-production oil formations or reservoirs without crude oil, it is necessary to add a breaker. [...

AI Technical Summary

Problems solved by technology

The water-based clean fracturing fluid is a cationic system, and octylphenol polyoxyethylene ether (OP-10) is used as a gel breaker. The nonionic surfactant OP-10 can break the ammonium salt cationic surfactant gel, but the use concentration is high, and the gel breaking speed is too fast, but the clean fracturing fluid cannot be broken when the use concentration is low

[0005] Some literatures have introduced the gel-breaking effect of natural gas on clean fracturing fluid. Natural gas cannot completely break the gel of clean fracturing fluid; However, if the amount added is small, the clean fracturing fluid cannot break the gel, and if the amount is too large, the clean fracturing fluid will break the gel too quickly, that is, the gel breaking time cannot be controlled, and the needs of fracturing construction cannot be met.

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